Lolbot

Overview

Worm:Win32/Lolbot is a notorious worm and remote access trojan that achieved massive global distribution by hijacking instant messaging platforms—including Skype, MSN Messenger, ICQ, and Facebook Messenger—to transmit malicious social engineering lures containing weaponized links. Once a recipient opened the link, Lolbot infected the workstation, propagated itself to the victim's entire contact list, and replicated across connected USB removable storage drives using deceptive LNK shortcuts and autorun scripts. In addition to peer-to-peer transmission, Lolbot acts as a multi-purpose crimeware backdoor: it hooks web browser and system APIs to intercept online banking credentials, drops secondary cryptominers and ransomware payloads, and enlists compromised machines into distributed denial-of-service (DDoS) botnets commanded over HTTP and IRC channels.

Known aliases

Threat reports may refer to this family under multiple names:

• Lolbot
• Worm:Win32/Lolbot
• W32/Lolbot
• Trojan.Win32.Lolbot
• Worm.Win32.Lolbot
• Lolbot.A
• Lolbot.B

Threat Actor Attribution

Attribution is probabilistic, not a science. Each link below states its confidence level and the evidence behind it.

• Global Cybercrime Syndicates High confidence
  Basis:

Family Pedigree & Lineage

Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:

Known Derivatives & Downstream Variants: Lolbot.A (Skype Worm) · Lolbot.B (Banking/Miner Stage) · Lolbot Usb Shortcut Spreader

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:

Tactical Mitigations

Based on the techniques used by this family, consider the following defensive strategies:

• T1056.001: Implement Endpoint Detection and Response (EDR) to monitor for suspicious API calls related to keystroke interception. Enforce Multi-Factor Authentication (MFA) to render stolen passwords useless.
• T1059.003: Restrict execution of Windows Command Shell (cmd.exe) and block unauthorized batch scripts.
• T1071.001: Implement web filtering and SSL/TLS inspection to detect malicious command and control (C2) traffic hiding in HTTP/HTTPS.
• T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.
• T1566.002: Inspect email links for known malicious domains and use link-rewriting services for time-of-click analysis.

MITRE D3FEND™ Defensive Countermeasures

Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):

Exploited Vulnerabilities (CVEs)

This malware family is documented weaponizing the following common vulnerabilities and exposures:

• CVE-2010-2568 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).
• CVE-2012-0158 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).

Command & Control (C2) and Network Profile

How this family talks to its operators. C2 traffic can often identify a family even when its code and configuration are hard to analyse. Ports and patterns are historical and change between campaigns, so use them as hunting leads rather than block-only rules.

Indicators of Compromise

Public indicators drawn from CISA advisories and vendor reporting. These are historical and intended for retrospective threat hunting; current campaigns may use different infrastructure. SystemHelpDesk adheres to responsible disclosure and does not host live samples.

File hashes (SHA-256, sample)

Cryptographic hashes serve as reference indicators for triage and detection rules. In accordance with responsible threat intelligence disclosure, this catalog indexes reference metadata and does not host or distribute live malware binaries.

• e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
• 7d389a9f24823126bebeea2ba470e8f80459c5d003b1238bfab5f58c704f056d

Delivery vectors

• skype_instant_messages
• usb_shortcut_propagation

Persistence mechanisms

• HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
• Windows Startup Folder Shortcuts

Tiered Detection Rules (Cisco CAIRN Model)

Modern threat detection requires multi-layered rule engineering. We classify detections into three operational tiers based on signal fidelity:

rule MALWARE_WIN_LOLBOT_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Lolbot"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "lolbot" ascii wide nocase
        $s2 = "lolbot" ascii wide nocase
        $s3 = "worm:win32/lolbot" ascii wide nocase
        $s4 = "w32/lolbot" ascii wide nocase
        $s5 = "trojan.win32.lolbot" ascii wide nocase
        $s6 = "worm.win32.lolbot" ascii wide nocase
        $s7 = "lolbot.a" ascii wide nocase
        $s8 = "lolbot.b" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Lolbot (Worm) Execution & Triage
id: 3ad7365c-8079-5749-b037-ff65a84ce7b1
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Lolbot malware family. Detects suspicious execution from temporary user
  directories with hidden window flags and background transfer utilities.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/lolbot
- https://malware-families-catalog.systemhelpdesk.com/defensive/ransomware-protection
- https://malware-families-catalog.systemhelpdesk.com/
author: Ricky Jordan, Lead Threat Intelligence Analyst, SystemHelpDesk MSP
date: '2026-10-14'
modified: '2026-10-14'
tags:
- attack.worm
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1566_002
- attack.t1091
- attack.t1059_003
- attack.t1056_001
- attack.t1055
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \cmd.exe
    - \powershell.exe
    - \cscript.exe
    - \wscript.exe
    CommandLine|contains:
    - AppData\Local\Temp
    - -WindowStyle Hidden
    - /e:jscript
    - bitsadmin /transfer
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: medium

rule MALWARE_WIN_LOLBOT_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Lolbot tradecraft"
        tier = "T3 - Attribution Fingerprint"
        confidence = "High (Confirmed Family Signature)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        // Core family identifier & heuristic payload signatures
        $attrib_str = "lolbot" ascii wide nocase
        $pe_magic = "MZ" ascii
        $net_marker = "http" ascii nocase
    condition:
        uint16(0) == 0x5a4d and ($attrib_str and $net_marker) and filesize < 15MB
}

Containment & Response Steps

Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.

1. Terminate suspicious processes executing from temporary directories and user AppData folders.
2. Scan and disinfect removable USB flash drives to neutralize hidden malicious LNK shortcuts.
3. Block outbound HTTP and IRC connections to unclassified external C2 domains.
4. Educate end users on identifying automated social engineering spam sent across collaboration apps.

What to Avoid

Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.

1. Do not click unsolicited links or download attachments sent through instant messaging applications.
2. Avoid inserting unverified USB flash drives into sensitive enterprise workstations.
3. Never disable operating system hidden file viewing settings that reveal hidden worm binaries.

References & External Analysis

• Microsoft Security Intelligence: Worm:Win32/Lolbot Technical Guidance
• Trend Micro Security Intelligence: Lolbot Analysis
• NIST National Vulnerability Database CVE-2010-2568
• Search "lolbot" on VirusTotal (External Analysis)
• Search "lolbot" on Any.Run (Sandbox Sandbox)
• Search "lolbot" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Worm)

Explore other documented threats in the same operational category:

• Kolabc
• Warezov
• Mabezat
• Hworld
• Brontok
• Vbs_Worm_Generator
• Beebone
• Ludbaruma

Machine-readable

Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/lolbot.json

Ecosystem & Interactive Environments

This profile is part of the Malware Families Catalog, a public dataset of 2,899 malware families. The catalog is also published across our ecosystem: Hugging Face, Kaggle, Zenodo, Replit, StackBlitz, CodeSandbox, and CodePen.